Hi Guys,

My name is dave, and this is my first post here . Hello!

Ive recently upgraded from a P38 to an L322. Much better car inside!.

I bought it with significant timing chain issues (collapsed guides) and vanos issues. I do a lot of mechanical work, and love working on cars in general.

I have replaced the timing chains, chain guides, etc and have fixed the vanos units using the Besian method and parts.

Everything is running nicely now, and the engine is super smooth, however there is one strange noise coming from the left side of the engine.

Its hard to explain, but it almost sound like a "buzzing" noise.

I took both belts off and started then engine for about 10 seconds, and the noise stayed. So I know its not a pulley, power steering pump, water pump, air con, or anything else hooked up to the belts.

It does however appear to be RPM effected. IE: As the RPM goes up, the noise gets louder.....

The noise is NOT evident at all when the car is at idle. The noise is only evident above about 2000 RPM. Additionally it ONLY happens once the car is started from stone cold, and has warmed up for a few minutes. IE: If started stone cold, and brought straight to about 2000 RPM, the noise is NOT there for the first few minutes. Once warm, if i turn the engine off and start it again it is still there (above about 2000 rpm).

Here is a youtube video of the noise ->
Im really stumped by this. Ive pulled the upper timing cover off to ensure the chain guides have not failed etc, and they all look fine to me.

Can anyone lend any suggestions as to what this might be?.

Many thanks guys.!

Dave